Fig. 4From: Light Trapping Enhancement in a Thin Film with 2D Conformal Periodic Hexagonal ArraysPhotographs and the absorption curves of the four samples. a Photographs of 4-in. wafer-sized samples with infrared wavelength (2300 nm), mid-wavelength (640 nm), and sub-wavelength (300 nm) periodicities as well as a planar reference. b The measured absorption spectra of all four samples. The thickness of the a-Si layer and Ag layer is 160 and 200 nm, respectivelyBack to article page